IMPROVEMENT OF SUBENDOCARDIAL MYOCARDIAL PERFUSION AFTER PERCUTANEOUSTRANSLUMINAL CORONARY ANGIOPLASTY - A MYOCARDIAL CONTRAST ECHOCARDIOGRAPHY STUDY WITH CORRELATION BETWEEN MYOCARDIAL CONTRAST RESERVE AND DOPPLER CORONARY RESERVE

Background After angioplasty coronary reserve improves but does not no rmalize in most patients. The purpose of this study was to examine bef ore and after angioplasty coronary reserve and transmural myocardial b lood flow distribution using myocardial contrast echocardiography. Met hods and Results Twelve patients with left anterior descending coronar y artery stenosis were investigated-before and immediately after angio plasty. A Doppler catheter was placed in the proximal segment. Myocard ial contrast echocardiography was performed by imaging the septum in M mode in a parasternal view using a 3.0-mL bolus of sonicated amidotri zoate sodium meglumine through the guiding catheter. The gray level be fore injection was subtracted from the gray level after injection to m aximize contrast time-intensity curves. The area under the curve was u sed as an indicator of myocardial blood flow, and subendocardial/subep icardial ratios were measured. After baseline measurements were obtain ed, Doppler and echographic data were recorded after a bolus infusion of papaverine into the left main coronary artery. The same protocol wa s performed in patients after angioplasty and in five control subjects with normal coronary arteries. Before angioplasty, echocardiographic and Doppler coronary reserve were 2.57+/-0.48 and 2.54+/-0.57, respect ively. Both increased after angioplasty to 3.65+/-0.57 and 3.36+/-0.70 , respectively (P<.05). Coronary reserve values obtained in patients w ith these two methods under the different conditions and in control su bjects were correlated (r=.81; P=.0001). Before angioplasty, subendoca rdial/subepicardial septal ratios decreased from 0.80+/-0.48 to 0.60+/ -0.27 after papaverine (P<.05). However, after angioplasty, these rati os tended to increase, from 0.72+/-0.27 to 0.92+/-0.45 after papaverin e, but they did not change in control subjects (1.11+/-0.23 to 0.92+/- 0.11). Conclusions These results show that myocardial contrast echocar diography yields flow reserve values that correlate with values obtain ed using intracoronary Doppler. This technique may be considered as an accurate tool to assess coronary reserve in humans.